The invention relates to a device for checking the leak tightness or leakage testing of containers, in particular, polyethylene terephthalate (PET) bottles under internal pressure, comprising a probe that can be brought into contact with a deformable container in a probing movement, a drive unit for the probe and a measuring device coupled to the drive unit and/or the probe for determining the container leak tightness by evaluating the probing movement. The invention also relates to a corresponding checking method.
WO-A 99/15871 discloses a device of the type in question and a method that can be carried out with it, in which a probing member is pressed against a container wall by a predetermined advancement of a sensing unit, the probing member being supported on the sensing unit by way of a compression spring. The end position of the probing member in the advancing movement is then detected as a measure of the gas pressure. Problematic aspects here appear to be the complex mechanical construction and the required positioning accuracy as well as possible influencing of the measuring accuracy by tolerances in the diameters of the bottles.